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Authors
Abstract(s)
A crescente preocupaĆ§Ć£o com o meio ambiente tem levado ao desenvolvimento de
alternativas sustentĆ”veis, principalmente na indĆŗstria de embalagens alimentares. Uma
das soluƧƵes encontradas tem sido a utilizaĆ§Ć£o de embalagens de biopolĆmeros
biodegradĆ”veis, pois tĆŖm capacidade de aumentar a seguranƧa e o tempo de prateleira
do alimento embalado e contribuem positivamente para a economia circular. Contudo,
os filmes de biopolĆmeros caracterizam-se por apresentarem fracas propriedades
mecĆ¢nicas e de barreira. Deste modo, o objetivo deste trabalho foi produzir um
trilaminado de pululana/celulose/zeĆna reunindo as vantagens de cada biopolĆmero
individual e ainda, atribuir-lhe propriedades antioxidantes e antimicrobianas por
incorporaĆ§Ć£o do Ć³leo essencial de esteva (OEE) (Cistus ladanifer L.). Assim,
produziram-se filmes de zeĆna e pululana pelo mĆ©todo de evaporaĆ§Ć£o do solvente. De
seguida, com ajuda dos respetivos solventes, procedeu-se Ć produĆ§Ć£o dos trilaminados
por calandragem. Foram desenvolvidos dois tipos de trilaminados:
pululana/celulose/zeĆna (PM) e pululana/zeĆna/celulose (PF). A microestrutura dos
trilaminados foi observada por microscopia eletrĆ³nica de varrimento e, posteriormente,
os trilaminados foram caracterizados quanto Ć s suas propriedades mecĆ¢nicas, Ć³ticas, de
barreira, antioxidante e antimicrobiana. Por fim, os trilaminados foram empregues
num modelo alimentar e a sua biodegradabilidade foi ainda avaliada. Concluiu-se que a
adiĆ§Ć£o da celulose melhorou as propriedades mecĆ¢nicas dos trilaminados, enquanto o
filme de zeĆna teve maior impacto nas propriedades de barreira. JĆ” a incorporaĆ§Ć£o do
OEE atribuiu ao material propriedades antioxidantes e antimicrobianas, com maior
efeito em bactƩrias Gram-positivas. Relativamente aos resultados obtidos no modelo
alimentar, verificou-se que os laminados PF sĆ£o mais prĆ”ticos no manuseamento e
mais eficazes durante o armazenamento do alimento. Tanto os laminados PM como PF
demonstraram elevada biodegradabilidade.
The growing concern with the environment has led to the development of sustainable alternatives, especially in the food packaging industry. One of the solutions found was the use of biodegradable biopolymers packaging since they have the capacity to increase the safety and shelf life of the packaged food and positively contribute to the circular economy. However, biopolymer films are characterized by poor mechanical and barrier properties. Thus, the objective of this work was to produce a pullulan/cellulose/zein trilaminate combining the advantages of each individual biopolymer and to ascribe antioxidant and antimicrobial properties to the laminates with the incorporation of rockrose (Cistus ladanifer L.) essential oil (OEE). Thus, zein and pullulan films were produced by the casting method. Then, by using the respective solvents, the trilaminates were produced by calendering molding technique. Two types of trilaminates were developed: pullulan/cellulose/zein (PM) and pullulan/zein/cellulose (PF). The microstructure of the trilaminates was observed by scanning electron microscopy and then the trilaminates were characterized in terms of their mechanical, optical, barrier, antioxidant, and antimicrobial properties. Finally, the trilaminates were applied in a food model and their biodegradability was further evaluated. It was concluded that the addition of cellulose improved the mechanical properties of the trilaminates, while the zein film had a greater impact on the barrier properties. The incorporation of OEE ascribed antioxidant and antimicrobial properties to the material, with greater effect on Gram-positive bacteria. Regarding the results obtained in the food model, PF laminates were found to be more practical in handling and more effective during food storage. Both PM and PF laminates demonstrated high biodegradability.
The growing concern with the environment has led to the development of sustainable alternatives, especially in the food packaging industry. One of the solutions found was the use of biodegradable biopolymers packaging since they have the capacity to increase the safety and shelf life of the packaged food and positively contribute to the circular economy. However, biopolymer films are characterized by poor mechanical and barrier properties. Thus, the objective of this work was to produce a pullulan/cellulose/zein trilaminate combining the advantages of each individual biopolymer and to ascribe antioxidant and antimicrobial properties to the laminates with the incorporation of rockrose (Cistus ladanifer L.) essential oil (OEE). Thus, zein and pullulan films were produced by the casting method. Then, by using the respective solvents, the trilaminates were produced by calendering molding technique. Two types of trilaminates were developed: pullulan/cellulose/zein (PM) and pullulan/zein/cellulose (PF). The microstructure of the trilaminates was observed by scanning electron microscopy and then the trilaminates were characterized in terms of their mechanical, optical, barrier, antioxidant, and antimicrobial properties. Finally, the trilaminates were applied in a food model and their biodegradability was further evaluated. It was concluded that the addition of cellulose improved the mechanical properties of the trilaminates, while the zein film had a greater impact on the barrier properties. The incorporation of OEE ascribed antioxidant and antimicrobial properties to the material, with greater effect on Gram-positive bacteria. Regarding the results obtained in the food model, PF laminates were found to be more practical in handling and more effective during food storage. Both PM and PF laminates demonstrated high biodegradability.
Description
Keywords
BiopolĆmeros Celulose Embalagens Alimentares Laminados Ćleo Essencial de Esteva Pululana ZeĆna